Caption: Paterson lamp treating cancer. Patient's hand receives red light from a Paterson lamp during treatment for skin cancer. In 1996 the lamp, new to cancer therapy, has successfully treated 95 per cent of skin cancers in patient trials. The treatment known as photodynamic therapy (PDT), involves spreading a special cream on certain skin cancers which is taken up by the cancer cells. The lamp light then activates a drug in the cream which kills the cancer cells painlessly, without scarring. It is an improvement over certain lasers and is much cheaper. The Paterson lamp was invented by British researcher Dr Colin Whitehurst at the Paterson Institute in Manchester, England.